Radiological procedures, such as x-ray fluoroscopy, are used for diagnosing and treating many diseases. These radiological procedures are generally performed with computerized x-ray imaging systems. Most x-ray imaging systems typically include an x-ray source, an image intensifier and a recording medium.
A major concern in these procedures involves preventing direct exposure and scattered x-rays from reaching the image intensifier or image recording media of the x-ray imaging system. Direct exposure of x-rays to the image intensifier may damage the device and produce diagnostically useless images. The scattered x-rays are also a health concern for medical personnel who perform the procedures. These concerns are addressed by a collimator which collimates the x-ray beam to an extent minimally necessary for imaging the object of interest. Collimation substantially eliminates scattered radiation and improves the imaging quality of the object of interest.
During the x-ray imaging procedure, the collimator must be adjusted each time an image is taken to optimally cover parts of the image where there is no body part. In a typical x-ray imaging procedure, such as a peripheral angiography of the legs, contrast media is injected into a patient and is followed with the imaging equipment. The imaging equipment follows the contrast media by taking images at multiple stations along the legs. In a typical peripheral study of the legs, there may be as many as 5-7 stations. The collimator must be manually adjusted at each of these stations before the image can be taken. This entails manually setting the collimator at each station before a mask run, saving the settings, and retrieving them from a lookup table during actual image acquisition.
Manually setting the collimator increases the time and dosage of radiation to which the patient and the physician are exposed. Moreover, the physician's skill level and other human factors may result in poor images. Most importantly, while the physician is involved in the important activity of caring for the patient, it is preferable for the physician to have as few tedious distractions as possible.
Automatic collimation is an important application of smart image acquisition, which is a new technology with many potential benefits for diagnostic imaging. Peripheral x-ray imaging studies can benefit greatly from the implementation of automatic collimation methods and techniques.
Accordingly, there is a need for a method and system for providing reliable automatic collimation which is fast enough to implement during image acquisition.